Ignition timer for internal combustion engines



Jan. 21, 1958 o. H. THOMAS 2,820,857

IGNITION TIMER FOR INTERNAL COMBUSTION ENGINES Filed Nov. 29, 1955 IN VEN TOR. Orr in H. 777 omds Attorney United States Patent O IGNITION TIMER FOR INTERNAL COMBUSTION ENGINES Orrin H. Thomas, Williamsport, Pa., assignor to James L. Burke, Elmira, N. Y.

Application November 29, 1955, Serial No. 549,689 4 Claims. (Cl. 200-30) This invention relates to ignition timers for internal combustion engines and it consists in the constructions, arrangements and combinations herein described and claimed.

The present day ignition timers consist of a breaker point assembly wherein a contact mounted on a swinging arm engages a contact mounted on a stationary adjusting plate when an actuating cam is moved to its low side and moves away from the stationary adjusting plate when the cam is rotated to a high side. Such construcnon presents a source of motor inefficiency which finally results In motor failure, due mainly to the fact that the tungsten contacts do not remain in contacting engagement a suflicient length of time for proper current transmlSSlOIl during the closing period between the contacts, so as to adequately saturate the ignition coil. Also, in this construction of timer, a point flutter or point fly-back is inherent which causes a miss in the motor, particularly at high speeds.

It is therefore an important object of the invention to provide a novel construction of mounting one of the contacts in a reciprocable, as well as oscillatory manner and wherein a spring tension is embodied whereby the pair of contacts of the assembly will have a longer dwell period to the actual breaking of the current between the contacts, thus insuring complete saturation of the primary coil of the ignition system.

It is also an object of the invention to provide housings for the reciprocable oscillatable contact which are so constructed as to be readily installed on the varying styles of point adjusting plates as now appearing in various ignitron systems.

Additional objects, advantages and features of inventron will be apparent from the following description considered in conjunction with the accompanying drawing, wherein:

Figure 1 is a top plan view of a distributor, with the cover removed, having my point assembly installed therein.

Figure 2 is an enlarged cross section on the line 22 of Figure 1.

Figure 3 is a perspective view of the point adjusting plate shown in Figure 1.

Figure 4 is a top plan view of a distributor, with the cover removed, embodying a point adjusting plate of different construction from that shown in Figure 1, having my point assembly installed therein.

Figure 5 is an enlarged cross section on the line 5--5 of Figure 4, and

Figure 6 is a perspective view of the point adjusting plate shown in Figure 4.

A conventional construction of distributor 10 is shown in Figures 1 and 4, the cover having been removed.

The constructions are identical, except for the point adjusting plates and include a binding post 11 in circuit with a condenser 12 by means of an insulated cable 13. A point adjusting plate 14 is shown in Figure 1 and a point adjusting plate 14' is shown in Figure 4. These plates pivotally mount a breaker arm 15 as at 16, and each plate is formed with slots 17 and 18 for adjustment purposes and are maintained in such positions by a binding screw 19, the slot 17 receiving a guide pin 20. The breaker arm in each instance includes a rubbing block 21 positioned so as to engage a cam 22 urged into contact therewith by means of a spring 23, the cam being driven by a shaft 24.

The breaker arm 15 is provided with a fixed contact 25 which is complemental to a reciprocable and oscillatable contact 26 mounted in a metallic housing 27 and 27' respectively, each being suitably secured in an upright flange 28 of the point adjusting plates 14 and 14', as the case may be.

As clearly shown in Figures 1, 2 and 3, the adjusting plate 14 includes a lateral extension 29 in which the slot 18 is formed and which receives the binding screw 19. It will be noted that the screw 19 occupies a position directly beneath the housing 27 when secured to the flange which obviously would prevent or interfere with the tightening and loosening of the screw, which is required when adjusting the setting of the contacts 25 and 26. The housing 27 is therefore constructed so that a portion thereof may be detached from the housing which is permanently fixed to the flange 28, as will now be described, attention being particularly directed to Figure 2. The flange 28 is formed with an opening 30 which ordinarily mounts the shank of one of the contacts, but in the present instance, this opening receives a collar 31 integral with an end wall of an annular housing 32, thQ' C0 iiE1I being of a length to project beyond the flange, the end of the collar 31 being swaged so as to upset the metal around the opening as at 33, thereby securing the housing 32 to the flange 28. The housing 32 is interiorly threaded as at 34. The contact 26 includes a substantially spherical body 35 having a circular extension 36, the outer end of which is planiform for securernent of a tungsten contact element. A cup-like closure 38 is engaged with the threaded portion of the housing 32 and a helical spring 39 seated in the enclosure 38 exerts pressure upon the spherical body 35 and thus maintains the extension 36 in outwardly projected position and presents the contact element 26 in alignment for contacting engagement with the contact 25.

In this form the cup-like closure 38 may be readily detached from the housing 32 so that access may be had to the binding screw 19, for adjustment purposes.

In the form of the device shown in Figures 4 to 6, it will be seen that the slot 18 is so positioned in the point adjusting plate 14' as to afiord no difficulty in actuating the screw 19 for adjusting the contacts 25 and 26.

Attention is invited to Figure 5 of the drawing, wherein a cylindrical housing 37' is formed with an axially disposed collar 31 which is received through the opening 30 formed in the flange 28 of the adjusting plate 14', the end of the collar 31' being swaged to upset the metal and secure the housing 37' to the flange, as in the first form.

The body 35' is constructed as previously described and includes a helical spring 39' confined within the housing by means of a screw closure cap 40.

The operation of the ignition timers is identical and is substantially as follows:

The helical springs 38 and 38 respectively, urge the contact 26 or 26' into engagement with the contact 25 of the breaker arm 15. The spring tension on the breaker arm maintains the contact 26 or 26 in a slightly retracted position, and upon rotation of the cam 22 to bring a high point of the cam into engagement with the rubbing block for separating the contacts, the contact 26 or 26 Patented Jan. 21, 1958 will continue to advance toward the contact 25 until the contacts have reached a separation point. Thus the advancing movement of the contact 26 or 26', as the case may be, prevent fly-back or fluttering between the contacts, at the time that the rubbing block leaves. a high point of the cam. While the contact 26 or 26 partake of a reciprocating movement, they also have a slight oscillatory motion due to the spherical construction of the body of the contacts, which motions tendto prevent pitting between the contacts.

It will be understood that adjustment of the contact 26 or 26 may be obtained by tightening or loosening the closure caps 38 and 40, as well aspermitting-renewalof th: contacts when required.

While I show and describe, preferred. forms of the device, this is byway of illustration only, and I consider as my'own. all such modifications in construction as. fairly. fall within the scope of the appended claims.

lclaim:

1. An ignition timer for internal combustion engines comprising an adjusting plate including a mounting screw, said plate having an upright flange, an opening being formed in said flange, a hollow housing having a wall at one end and having an axial opening therethrough; a collar surrounding said opening-and projectingtherefrom, said collar beingof a diameter for passage through the opening of said flange and projecting therefrom, the' end of said collar being swaged for se'curing-saidcollar within the opening of the flange, said housing being provided with interior screw threads, a substantially spherical body member in said housing and having a circular extension reciprocably mounted'in said collar and projecting therefrom, a contacton' the projecting'endofsaid extension,-a removable closure cap for' said hollow housing, a helical spring interposed between saidclosure cap and the substantially spherical body member urging said circular extension and contact outwardly of said collar, a spring pressed swinging arm mounted on said adjusting plate, said arm having a contact aligned with and engaging the first named contact and a rotary cam member for effecting intermittent movement of said swinging arm.

2. The structure of claim 1, in which said mounting screw is positioned beneath said hollow housing.

3. The structure of. claim 1,,inwhich said substantially spherical body member may partake ofoscillatory movements.

4. An ignitiontimer ior i'nter-nal combustion engines comprising an adjusting plate having an upright flange having an opening-formed,;therein, .a hollow housinghaving an axial collar projecting therefrom, said collar being of a diameter for passage through the opening of said flange for securement therein, said hollow housing being provided with screw threads, a substantially spherical body member in, said, housing, and having a. circular extension reciprocably mounted in said, collar. and. projecting therefrom, a contact on the projecting. end of said. extension,

a closure cap for said hollow housing threadedly engaged.

with the screw threads of said housing, a helical spring interposedbetween said closure cap-and the-substantially sphericalbody member urging said' circular extension andcontact outwardly of said collar, a spring pressed swinging arm; mounted, on saidadjusting plate, sai'darm having a. contact-aligned with and engagingthe firstnamed contactv and a rotary'cam member for eflecting intermittent movemenrofi'said swinging arm.

References-'Cited" in *thefile or' this patent UNITEDv STATES. PATENTS 

